The injury Green had would be fairly easily fixed today. Unfortunately, back then it was career ending. He could have been quite good.
The foot issue Parker has can be fixed and essentially was fixed. But they wanted to be sure it was fine so this is kinda an elective surgery to make sure it is right. Better lose a little training camp now and be certain it will not become a recurring issue.
Parker will be fine. The only question is how the missed time to gel with Tannehill effects their chemistry, and how quickly he can sharpen up his route running after the rehab is done.
Given how natural he looked in OTA's and his 80" wingspan, and exceptional ability to adjust to the throw, and soft hands ... I think the chemistry will be fine.
Route running takes time and practice, but Parker is a hard worker and I have faith Tannehill is willing to put in the extra reps to get Parker up to speed quickly.